1. Field of the Invention
This invention relates to a motorized watercraft with a hull of the craft, on which the user lies prone or stands, with a flow channel extending in the hull of the craft with a motor-driven water screw, wherein an electric motor and batteries, as well as a control device for the electric motor are housed in the hull of the craft.
2. Description of Related Art
A motorized watercraft of this type is known from PCT International Publication WO 96/30087. There, the user lies prone on the hull of the craft, and the water screw in the flow channel is driven by a battery-powered electric motor so that a water flow is aspirated through the flow channel which extends opposite the movement direction of the motorized watercraft. Thus the water flow can be kept away from the user, and the flow of the channel water can also be conducted past the user by means of the shape of the hull of the watercraft. This simplifies swimming and diving with the motorized watercraft.
The design of the structure of the motorized watercraft is complicated and is not user-friendly with respect to maintenance.
It is one object of this invention to simplify a motorized watercraft of the type mentioned above and to design it user-friendly.
In accordance with this invention, this object is attained with the water screw, the electric motor and the control device designed as an underwater drive unit and placed in the flow channel. The batteries for the electric motor are placed into a separate housing, installed in the hull of the craft so that it can be exchanged.
The combination of the water screw, the electric motor and the control device for the electric motor into one underwater unit, and their placement in the flow channel results in a considerable simplification of the structure of the elements, in particular the hull of the craft, and of the maintenance of the motorized watercraft. The batteries placed in a separate housing can be easily removed for charging and can be replaced by a new housing containing charged batteries.
This rapid replacement makes the motorized watercraft particularly ready for use and is therefore user-friendly, since it can be employed very rapidly.
Because the electric motor is seated directly in the flow channel, it is cooled by the water flow. Thus it is possible to omit additional cooling devices and the parts outlay or cost for the motorized watercraft is considerably further reduced. If required, the control device can also be cooled in the same way.
If the hull of the craft has a surface for prone use or a platform for the user above the flow channel, it can be used in two ways.
The construction can be further simplified by forming the flow channel as one piece with the hull of the craft.
In one embodiment which is particularly advantageous, the flow channel starts with an inflow opening in the area of the bow of the hull of the craft and terminates in an outflow opening in the area of the stern of the hull of the craft. The underwater drive unit is installed in the flow channel as a suction device.
In accordance with one embodiment, the housing of the batteries is such that the housing with the batteries is inserted into a recess formed in the underside of the hull of the craft which is arranged outside of the flow channel and the inflow opening in the area of the bow of the hull of the craft.
In one embodiment, there are two different types of employment of the motorized watercraft while in the prone or standing position. A remote control device is assigned to the underwater drive unit, which is releasably attached to the hull of the craft and can be brought into operative contact with the control device of the underwater unit over a wireless transmission path.
For a simple maintenance or repair of the underwater drive unit, the hull of the craft has a plate, flap or the like, which can be opened, in the flow channel below the underwater drive unit, through which there is access to the underwater unit.